I acquired a new mac mini late 2012 with a fusion drive & a 2,6 Ghz cpu. It came with maverick.

The machine already came back last week from a mac repear shop where they changed the mother-card because its power turns off on its own while asleep. This did not do much because it still does it. I should either take it back or call apple to have it changed I suppose, except that now...

Now it seems I'm in dire straits. Even before I wiped Mac HD, erasing the Recovery disk went wrong. It left a partition named "blank" weighting about 16 Mo (originally 650Mo) that doesnt show up in the partition part of disk utility. This "blank" partition also showed up on the desk.
I've created an ML bootable USB stick with diskmaker but I can't use it, the machine does not want it. I'll spare you the details (blank screen, folder question mark, the globe, asking for the wifi key, error 1005F & s.o. I also tried the target mode with 2009 mac mini with ML, but I got a message error saying disks were not compatible. Is this because of the fusion drive ? Whatever...

My machine is still under warranty for 2 years & now I'm scared to lose this warranty if I mention my stupid endeavours to apple support. Needless to say, I'm a complete newbee to mac os instal since I rarely change machines. I went into Terminal doing paste & copy just to wipe the recovery hd as mentioned in the method above.

I think I'm in trouble, my videos helps making ends meet. All I can think off is to bring it back as is to the repear shop & ask them to fix the or replace it with ML. I stumbled on a topic mentioning the recovery hd on you site. to

Apple won't cease to support your hardware if you choose to install old / custom OS. At worst, they will assist you in wiping the drive and getting the minimum supported version for your hardware running. I'll see if I can answer the primary portion of your question - feel free to edit out the worry about warranty or ask that as a stand alone question if you still worry there.
– bmike♦Oct 6 '14 at 17:52

1 Answer
1

Since you have AppleCare, you can actually call them and ask how to install a specific version of the software and be supported on how to install things.

In a nutshell, you'll have to use Internet Recovery to wipe the drive and get back to the version of OS that shipped with your Mac. From that point, you can download the older OS from the App Store (AppleCare may have to issue you a redemption code for that build if you don't have it for your Apple ID).

From there, you can partition your internal drive and install Mountain Lion on a separate partition or install it onto a USB drive.

At that point, you can restore your data and settings on to Mountain Lion and/or wipe the internal drive booting off the external to finally install Mountain Lion as the only OS on the internal drive.

It's a bit of an exercise, but you can ask here or from Apple for guidance on each step along the way if you get lost.

Maybe it's worth adding that Internet Recovery will use the OS X which was installed when the Mac was first shipped. That means on one side that it will be the "oldest" OS X you can downgrade to but in your case that ML is installable. When I recall right, you have to just use Internet Recovery and wipe your drive. Them install from scratch and load data via a Time Machine Backup. I've done this before and as far as I remember it worked. Let us know how you're getting on. This may also help discussions.apple.com/docs/DOC-1948.
– fsimkovicOct 6 '14 at 21:35